Dwyer Instruments offers a full line of flow switches. Paddle flow switches include the Series FS-2, V4 Flotect vane operated, V6 Flotect mini-size, V7 Flotect vane operated, V8 vane operated, and V10 Flotect mini-size. The shuttle/piston flow switch options are the Series AFS adjustable, G9 globe, GVS globe valve, P1 brass, P2, P3 polypropylene, P4 PPS piston, P5 PVC shuttle, and many others.

Rheotherm flow switches by Intek provide switch protection in all types of liquids or gases, and are capable of monitoring various flow switch applications, from extremely low flow process additives to loss of flow protection in large water or air lines. These flow switches, which have no moving parts, are offered in four models. The general purpose 100CS is the lowest cost industrial option and comes with one SPDT relay; the 100FS, for hazardous locations, has one SPDT relay with an option for a second relay for high and low set points; the Model 400 has an insertion probe with MNPT fitting, and is meant for hazardous settings; and the 500 provides an in-line design with  one N.O. relay rated at 0.5 A at 200 Vdc max and choice of 0.0625" or 0.125" O.D. flow tube connections.

Cole-Parmer provides three main categories of flow switches. The compact low-flow switch is for use with liquids at 0.05 GPM, with a max pressure of 150 psi at 70 degrees Fahrenheit. The normally open SPST switch features a dual-diameter internal bore and piston configuration, and can be used up to 1.0 GPM and 200 psi. The mini low-flow switch is meant for liquids and gases at a max psi of 1500 and 500 cc/min. In addition, the company offers Flowline flow switches for process control, liquid flow switches for threaded plastic piping (0.25 GPM), and adjustable industrial flow switches for liquids and gases.

Fluid Components International (FCI) use thermal dispersion technology to measure liquid or air flow pressure which drive adjustable-setpoint alarms. The FlexSwitch Series is for process temperature changes up to +/-100 degrees Fahrenheit, and includes insertion and in-line options. The company also offers a universal analyzer flow switch and monitor called the FS10A; it has 0.25" NPT and is compatible with 0.25", 0.375", and 0.5" tube tees, and offers reading accuracy of +/-1% for gases or +/-5% for liquids. Rounding out FCI's products are the two-wire loop NuTec 2000 Series (for non-intrusive, high flow, high purity environments), the RF Series for reverse flow, and the BASIC Series for general purpose and premium flow, as well as temperature monitoring.

Omega Engineering offers an array of flow switches for air, water, or oil that are designed to meet specific standards. These switches allow for maximum flow rates between 0.5 and 200 GPM (or 5 to 1,000+ SCFM), maximum pressure settings from 100 to 5,000 psi, accuracy between 2% and 25%, and temperatures up to 599 degrees Fahrenheit. Switch types are available as either mechanical and thermal.

Thermal Instrument Company offers two basic models of flow switches: the Model 62-9 thermal insertion probe and the Model 600-9 in-line meter. The 62-9 measures the flow rates of gases, liquids, or slurries in stacks, irregularly shaped lines, and product ducts. It can be customized with extra length for insertion through a gate valve or packing gland, and/or with sensors made of platinum and embedded in a ceramic matrix for applications over 350 degrees Fahrenheit. The Model 600-9 can handle liquids, slurries, gases, and homogeneous solids , and is built onto a spool that matches the actual flow pipe dimensions and construction material; minimum size is 0.0625" in diameter, but there is no maximum size.

SOR offers three types of flow switches. The vane operated flow switch is designed for direct sensing of liquid flow in pipelines, and is magnetically actuated; it can be used in pressures up to 1480 psi and 800 degrees Fahrenheit. The OEM flow switch is vertically mounted and vane operated, and is suitable for plant and OEM applications where open or closed contacts are required to signal flow or no flow conditions. The Model T21 Point Level Switch uses thermal differential technology to measure liquid flow, level, or interface; it offers a wide operating temperature range (-100 to +392 degrees Fahrenheit) and a self-heating sensor design.